net/disk_cache/simple/simple_entry_format_history.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_FORMAT_HISTORY_H_
   6 #define NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_FORMAT_HISTORY_H_
   7
   8 #include <stdint.h>
   9
  10 #include "base/basictypes.h"
  11 #include "net/base/net_export.h"
  12
  13 namespace disk_cache {
  14
  15 namespace simplecache_v5 {
  16
  17 const uint64 kSimpleInitialMagicNumber = UINT64_C(0xfcfb6d1ba7725c30);
  18 const uint64 kSimpleFinalMagicNumber = UINT64_C(0xf4fa6f45970d41d8);
  19
  20 // A file containing stream 0 and stream 1 in the Simple cache consists of:
  21 //   - a SimpleFileHeader.
  22 //   - the key.
  23 //   - the data from stream 1.
  24 //   - a SimpleFileEOF record for stream 1.
  25 //   - the data from stream 0.
  26 //   - a SimpleFileEOF record for stream 0.
  27
  28 // A file containing stream 2 in the Simple cache consists of:
  29 //   - a SimpleFileHeader.
  30 //   - the key.
  31 //   - the data.
  32 //   - at the end, a SimpleFileEOF record.
  33 static const int kSimpleEntryFileCount = 2;
  34 static const int kSimpleEntryStreamCount = 3;
  35
  36 struct NET_EXPORT_PRIVATE SimpleFileHeader {
  37   SimpleFileHeader();
  38
  39   uint64 initial_magic_number;
  40   uint32 version;
  41   uint32 key_length;
  42   uint32 key_hash;
  43 };
  44
  45 struct NET_EXPORT_PRIVATE SimpleFileEOF {
  46   enum Flags {
  47     FLAG_HAS_CRC32 = (1U << 0),
  48   };
  49
  50   SimpleFileEOF();
  51
  52   uint64 final_magic_number;
  53   uint32 flags;
  54   uint32 data_crc32;
  55   // |stream_size| is only used in the EOF record for stream 0.
  56   uint32 stream_size;
  57 };
  58
  59 }  // namespace simplecache_v5
  60
  61 }  // namespace disk_cache
  62
  63 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_FORMAT_HISTORY_H_